Lupus Anticoagulant Evaluation with Reflex

Test Code

7079

Alias/See Also

LAB478

CPT Codes
85613, 85730

Includes

PTT-LA and dRVVT with Reflex Confirmations

If PTT-LA Screen is prolonged (>40 seconds), then Hexagonal Phase Confirmation will be performed at an additional charge (CPT code(s): 85598).

If Hexagonal Phase Confirmation is positive or weakly positive, then Thrombin Clotting Time will be performed at an additional charge (CPT code(s): 85670).

If dRVVT Screen is prolonged (>45 seconds), then dRVVT Confirm will be performed at an additional charge (CPT code(s): 85597).
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If dRVVT Confirm is positive, then dRVVT 1:1 Mixing Study will be performed at an additional charge (CPT code(s): 85613).

Preferred Specimen

3 mL frozen, platelet-poor plasma collected in a 3.2% sodium citrate (light blue-top) tube

Minimum Volume

2 mL

Instructions

Platelet-poor plasma: Centrifuge light blue-top tube for 15 minutes at approximately 1500 g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/mcL). Freeze immediately and ship on dry ice.

Transport Container

Transport tube

Transport Temperature

Frozen

Specimen Stability

Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Hemolysis • Received thawed

Methodology
Clot detection

Setup Schedule

Mon-sat

Limitations

Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: no effect (panel includes mixing studies which correct for Warfarin-induced factor deficiencies); Heparin (UFH or LMWH): possible to misclassify as LA; Dabigatran or Argatroban (Thrombin Inhibitors): panel includes Thrombin Time (TT) which detects thrombin inhibitors, unable to detect if TT significantly abnormal; Rivaroxaban or Apixaban (Factor Xa Inhibitors): possible to misclassify as LA.

Reference Range

Lupus Anticoagulant	Not detected
PTT-LA Screen	≤40 sec
dRVVT Screen	≤45 sec

Clinical Significance

Lupus anticoagulants (LA) are members of a family of antibodies with phospholipid-protein specificity. LA may be defined as an immunoglobulin, IgG or IgM or a mixture of both, that interferes with one or more of the in-vitro phospholipid (PL) dependent tests of coagulation. These antibodies are not associated with a hemorrhagic diathesis, but rather have been linked to thrombotic events. In addition to thrombosis other clinical complications have been associated with the presence of LA. These include strokes, nonbacterial thrombotic endocarditis, livedo reticularis and a variety of obstetrical complications such as intrauterine fetal death, recurrent spontaneous abortion, fetal growth retardation, early onset preeclampsia and chorea gravidarum.

Note: Target specific anticoagulant therapy (anti-Xa medications, direct thrombin inhibitors) may cause false positive results.

Performing Laboratory

Quest Diagnostics Nichols Institute-San Juan Capistrano, CA

33608 Ortega Highway

San Juan Capistrano, CA 92675-2042

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.